So, I recently happen to visit this site: http://www.drupalla.com, and found it to be the amazingly similar to the Drupal Answers site. Moreover, it is similar to the design of the StackExchange network of sites.
To check this, I created a account on that site (used Google chrome to translate the site, as it is in Chinese language) and checked the features and found that its has almost the same features as the StackExchange sites.
It makes me feel good that one can use Drupal to built this type of sites, but I find it morally wrong.
Also on every page of any StackExchange site the following line appears at the very bottom:
site design / logo © 2012 stack exchange inc; ...
So, I feel this is a issue of copyrights infringement, which should be taken care of.